U.S. President Barack Obama is calling for a new era in trans-Pacific relations. In a speech in Tokyo, the president said America is determined to partner with Asia to meet the global challenges of today.

President Obama says America is and always has been a Pacific nation. "The United States of America may have started as a series of ports and cities along the Atlantic ocean, but for generations we also have been a nation of the Pacific. Asia and the United States are not separated by this great ocean; we are bound by it," he said.

Looking out at the crowd in a packed auditorium in Tokyo, Mr. Obama addressed the people of East Asia as extended family. He spoke of his childhood in Indonesia, and said he knows first hand the dynamism of the region. "There must be no doubt: as America's first Pacific President, I promise you that this Pacific nation will strengthen and sustain our leadership in this vitally important part of the world," he said.

He said America's commitment to the region begins with Japan, but does not end there. He said it is important to strengthen old alliances and build new partnerships, including with China. "I know there are many who question how the United States perceives China's emergence. But as I have said - in an inter-connected world, power does not need to be a zero-sum game, and nations need not fear the success of another. Cultivating spheres of cooperation - not competing spheres of influence - will lead to progress in the Asia Pacific," he said.

President Obama made clear he is seeking a delicate balance in relations with China - seeking cooperation on key global and regional issues, while keeping the human rights agenda very much alive. "The United States will never waver in speaking up for the fundamental values that we hold dear - and that includes respect for the religion and cultures of all people. Because support for human rights and human dignity is ingrained in America. But we can move these discussions forward in a spirit of partnership rather than rancor," he said.

The president - who will arrive in China on Sunday - did not specifically refer to Tibet. But he did call for action by Burma's leaders to free political prisoners and launch a dialog with democracy advocates. And he vowed greater engagement on this and other members with ASEAN, the regional grouping of Southeast Asian nations.

Overall, cooperation across the Pacific was the dominant theme of the president's speech. He spoke of the possibility of progress in areas ranging from the global economy to climate change and the challenge posed by North Korea's nuclear ambitions. "We will not be cowed by threats, and we will continue to send a clear message through our actions, and not just our words: North Korea's refusal to meet its international obligations will lead only to less security - not more," he said.

To cheers from his audience, the president reaffirmed America's commitment to the security of Japan and South Korea. And he said the United States seeks broader engagement throughout East Asia because closer ties and stronger cooperation across the Pacific will benefit all.